Inner tube for pneumatic tires and process of making the same



O. T. BUGS.

INNER TUBE FOR PNEUMATIC TIRES AND PROCESS OF MAKING THE SAME.

APPLICATION FILED JUNE 4, 1918.

Patented Feb. 3, 1920.

Jwvewtoz To all whom it may concern ownn r. BUGG, or PHILADELPHIA,PENNSYLVANIA.-

INNER TUBE'FOR PNEUMATICTIRES AND PROCESS OI? MAKING- THE SAME"Application filed June 4,

Be it known thatI, OWEN T. BUGG, a citizen of the United States,,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements in InnerTubes for Pneumatic Tires and Processes of Making the Same; and I dohereby declare the following to be a full, clear, and exact descriptionof-the invention, such as will enable others skilled 'in the art towhich it appertains to make and use the same.

This invention relates to inner tubes for pneumatic tires made of clothor other fabric, and has for; its object to improve the tubes of thisnature which have been heretofore proposed.

With these and other objects in view the invention consists in thenoveldetails of construction and combinations of parts more fully hereinafterdisclosed and particularly pointed out in the claims.

. Referring to the accompanyingdrawings forming a part of thisspecification in which like numerals designate like parts in all theviews.

Figure 1 is a diagrammatic view illustratin a mandrel with a portion'ofan inner tufie made in accordance with this'invention wound thereon Fig.2 is a .sectional view of a mandrel showing one half of my inner tubewound the mandrel shown in Fig. .2, after having thereon; I

Fig. 3 is a view similar to Fig. 2,showing the other half of my tubewound thereon d Fig. 4 illustrates the half tube made on V the mandrelshown in Fig. when detached from said mandrel;.

Fig. 5 illustrates the half tube formed on been detached therefrom; Fig.6 shows the half tube illustrated in.

Figs. 4and 5 connected together to form" a;

single complete inner tube; I

Fig. 7 is a sectional view showing an ordi nary tire with my inner tubein place therein;' and 5 1 Fig. 8 is an enlarged sectional view of aportion of the parts shown in ig. 7.

1 indicates a mandrel of the semi-circular section shown, aroundwhich ishelically wound one or more strips 2 of canvas or other suitable fabricmaterial, and on the outsideof said canvas strips 2 are wound the paperor other strips 3 m such a man- Specincatioii'bt Letters Patent.

19189 Serial n xa'ssaov.

ner as to cover the joints 4 made by the canvas strips. mandrel l-is ofring shape, and that it has. the inner flat surface 5 which causes thehalf tube 6, that is wound thereon, to be provided. with a correspondingfiat inner surface. Later when the said tube 6 is stripped from themandrel 1, as by slitting the same, along the line 7 the flat surface ofsaid tube is.converted into the two flat surfaces 8 and 9 bestillustrated in Fig. 4.

In the same way, there is wound on a similar but smaller ring likemandrel 10, the other half tube 11 which is likewise preferablymade ofhelically wound strips Patented Feb. 3, 1920.

It will be observed that-the ofcanvas and paper, and which when'providedwith the two fiat surfaces 13 and 14-, as best shown in Fig. '5.

The two half tubes'6 and 11 being thus slitted, and stripped from itsmandrel, is

formed on their respective mandrels 1 and l0, and stripped therefromthey' are brought together as shown in Fig. 6, whereupon the fiatsurface 8 is cemented, glued or other-' wise secured to the fiat surface13, and a flat surface 9 is similarly secured to the flat surface 14,leaving the joint 15 between the ends 'of said surfaces 8, 9, 13-and 14free to be penetrated by the air contained within the finished tube 16thus produced.

The glue or other cementing material is preferably not carried-out tothe circumferpoints such as 17 inside said circumference thus leavingaflexible portion of the front having the members 18-.and 1 9 on one sideof the tube, and the members 20and 21 on the other side of said tube.The tube being 9 thus formed itinay be inserted into an outer casing 20,of any suitable construction, and inflated the same as any othertube.

' 'brou ht into position andinfiated, the yielding exible surfaces orportions 18, 19, ,20

ence of the tube 16 but'is stopped at some When said completed tube 116is thus and 21 will receive the air pressure, will yield thereto, andcause the outer surface the interior surface of the casing. 20', andthus to resist a'll inward pressures and to form the resilient supportso much desired in pneumatic tires.

The edges 23 of the individual strips 2 of canvas are referablyabutted,as best shown in Fig. 8,' ut of course, they may be overlapped asdesired. The .individual strlps 3 22' of said tube 16130 accommodateitself-to, V

of, paper or other fibrous naterialmay be of a single thickness or of aplurality bf thicknesses as desired, andtheir edges preferably. overlapeach other, as best i l1us-' when fabric is substituted for'paper; Itreat it with a'rather thicker solution of pyroxy- -lin, cement, glue,or other material so as to render the same'absolute'ly air tight. The

paper strips 3 and canvas strips 2*are ce-' mented together by anysuitable and well known glu or othen material, but such material isselected as will best withstand the heat which is' generated onthesurfaces'be tweenthe inner tube and the outer casing. When it is desiredto repair the inner tube, as for example, after; a puncture, I

simply wrap paper'-- or prepared' fabric around the punctured part andglue the parts together as will be readily understood. From theforegoing, it will now be clear that by employing canvas or similarmaterial,

for the inner tube, I am enabled to utilize a comparatively inexpensivematerial posses sed of great strength, and by covering the joints 4 witha material impervious to air, I am enabled to make this inexpensive andvery stout tube air tight. On the other hand, as well known, it has notbeen possi ble'prior to my invention to render inflexible ornon-stretchable tubes of this character sufficiently resilient toaccommodate themselves to the varying pressures and loads to I flexibleportions 18, 19, 20 an '21, my tube. is rendered flexible and is given aproperty -which is the equivalentto a stretching 0 which they aresubjected and therefore they would burst under hard-usage, In my in*vention, on the other hand, by roviding the quality so that it willaccommedate itself to the highest pressures in a manner similar toarubber inner tube. In addition to the above, it has been found almostimpossible heretofdre. to helically wind a tubev of this nature onamandrel, to .then strip it from the mandrel and to effectually close'the joints rendered necessary by. the stripping actions well known.

On the other hand, by helically winding the inner tube in two halves asillustrate above, and providing the fiat surfaces 8, 9, 13 and 14, whichmay be glued together, I am enabled to effectually close the joint insuch a way that an internal rupturing pressure is 'not brought thereon,to any very great extent, and therefore, my joint remains perfectlytight no matter'how hard its usage may be.

It will thus be seen that although my inner tube is made of relativelyinflexible material such as canvas yet at .the same time, it ispossessed. of substantially all of the useful properties that a rubberinner tube ,would have. F

It is obvious that those skilled in the art may vary the details of theconstruction as well as the arrangement of parts without departing fromthe spirit of the invention,

and therefore, I do not wish to be limited to the above disclosureexcept as may be required by the claimsl What'I claim is .1. An innertube for pneumatic tires comprising an outer member half round in crosssection made from helically wound strips of fabric covered with materialimpervious to theair; and also comprising an inner member half round incross section also made from helically wound strips of cotton fabric andcovered with a material impervious to the air, said outer and innermembers being secured together ona common cross sectional diameterhaving readily yieldable portions at each end ofsaiddiameter,substantially as described. I, v

2. The process of maklng an -1nner tube for pneumatic tires wh chconsists in hellcally winding an outer member of said .tube

on a ring like mandrel halfmound in cross section, slitting the outermember thus formed on its fiat side and stripping it from said mandrel;helically winding an inner member on a ring like mandrel also half roundin cross section; slitting 'said inner member on its fiat side andstripping it from its mandrel; and securing together the cor-*responding fiat sides of-saidouter and inner members to form '.acompleted inner tube,

substantially as described. r 4 In testimony whereof (I affix mysignature, in presenceof two witnesses.

g v ow N T. BUGG.

' Witnesses:

I v W. J. LADBEIR,

. Fonn rssgmrrs;

